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42 Cards in this Set
- Front
- Back
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What constitutes a nutrient?
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Water
Carbs Lipids Proteins Vitamins Minerals |
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Caloric Intake Recommendations
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1600 - Women
2200 - Active women and most men 2800 - Teenage boys and active men |
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Who developed the food guide pyramid?
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U.S. department of agriculture
- it indicates the number of servings of each food group to eat each day |
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Where does mucosa fold into?
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Rugae
- increases surface area - allows stomach to expand - forms gastric pits - inside pits are gastric glands that secrete chemicals |
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What do mucous cell secrete?
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Mucus
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What do chief cells secrete?
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pepsinogen
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What do parietal cells secrete?
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HCl - hydrochloric acid
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What do G cells secrete?
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Gastrin hormone (blood)
- it release more gastric juice - increases gastric motility - relaxes the pyloric sphincter |
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Describe the muscularis
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3 layers of smooth muscle
It causes greater churning and mixing of food with gastric juice |
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Explain the process of swallowing?
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Your tongue voluntarily pushes food to back of mouth. During the involuntary phase (pharynx stage) breathing stops and airways are closed. Peristalsis pushes food down.
Total travel time is 4-8 sec for solids and 1 sec for liquids The lower sphincter relaxes as food approaches |
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What is Gastroesophageal Reflex Disease?
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GERD
The lower esophageal sphincter fails to close which means: - stomach acid enters the esophagus and causes heartburn - if you have a weak sphincter you should eat a large meal and lay down - smoking and alcohol can make the sphincter relax - you should avoid coffee, chocolate, tomatoes, and fatty foods. - should try to neutralize stomach acids |
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What are the parts of the stomach?
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Cardia
Fundus Body Pylorus - narrows as it reaches the pyloric sphincter |
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What happens when the stomach empties?
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small bits of chyme leave through the pyloric sphincter.
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What are the two types of digestion in the mouth?
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Mastication/chewing
Chemical |
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What does mastication consist of?
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breaks food into pieces
when food mixes with saliva it forms a bolus |
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Chemical Digestion in the mouth
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amylase begins starch digestion.
lingual lipase (glands in tongue) begins the breakdown of triglycerides into fatty acids and glycerol. |
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What is the pharynx?
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Tube from internal nares to the esophagus.
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Describe digestion through pharynx
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swallowing facilitated by saliva and mucus.
bolus is pushed fown into oropharynx. soft palate lifts to close nasopharynx. larynx lifts and epiglottis covers glottis. |
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Describe Esophagus
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Collapsed muscular tube
mucosa - stratified squamous submucosa - large mucous glands muscularis - upper 1/3 is skeletal, middle is mixed, lower 1/3 is smooth lower esophageal sphincter (cardiac) seperates esophagus from stomach |
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What are primary or baby teeth?
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20 teeth that start emerging at 6 months
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What are permanant teeth?
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32 teeth (by adulthood)
incisors for biting canines for tearing premolars and molars for crushing and grinding food |
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What are the salivary glands?
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parotid
submandibular sublingual |
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What are the functions of saliva?
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wet food for easier swallowing.
bicarbonate ions buffer acidic foods chemical digestion of starch and enzyme (salivary amylase) enzyme (lysozyme) helps destroy bacteria protects mouth from infection in rinsing action 1-1.5 qts a day |
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What is the muscularis?
of esophagus |
Skeletal muscle - mostly voluntary
- in mouth, upper esophagus and anus - control over swallowing and defacation smooth muscle- involuntary longitudinal and circular - mixes, crushes and propels food along by peristalsis |
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what is the serosa?
of esophagus |
covers all organs and walls of cavities
secretes slippery fluid inner layer of peritoneum areolar connective tissue (internal) epithelial (external) |
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Describe the mouth
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lips and cheeks keep food in mouth
ends at oropharynx tongue - skeletal muscle moves food for chewing and swallowing taste buds for taste speech |
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Layers of the GI tract
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muscosal layer
submucosal layer muscularis layer serosa layer |
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Steps of the digestion process
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ingestion - take food in mouth
secretion - cells and glands secrete 7L of digestive juices mixing and propulsion - contraction of smooth muscle, move food down GI tract digestion - break food down into molecules absorption - fluids and molecules pass into epithelial lining defecation - material that was not absorbed |
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physiology - describe mechanical digestion
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mixing waves
every 15-25 secs to mix bolus and gastric juice and that makes chyme (thin liquid) travels from stomach to pyloric region open pyloric sphincter and squirt out 1-2 tsp of chyme |
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physiology - chemical digestion
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protein digestion begins
HCl denatures (unfolds) proteins HCl transforms pepsinogen into pepsin pepsin breaks amino acid peptide bonds fat digestion continues gastric lipase splits triglycerides HCl kills microbes in food mucous cells protect stomach walls from being digested with 1-3 mm thick layer of mucus |
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Anatomy of the small intestine
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3 m long, 2.5 cm diameter
large surface area for majority of digestion and absorption 3 parts duodneum jejunum ileum |
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Describe the small intestine
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have structures that increase surface area
1. circular folds permanant 1 cm folds cant stretch like rugae in stomach |
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Describe the villi
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projections of mucosa
contain capillaries |
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Describe the microvilli
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cell surface has projections - brush border
absorption and digestion digestive enzymes on brush border |
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Cells of Small Intestine
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secrete alkaline intestinal juice
absorptive cell - digests/absorbs nutrients goblet cell - secretes mucus enteroendocrine cell - secretes hormones -secretin cholecystokinin paneth cells -secretes lysozome |
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Secretion of enzymes through liver
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bile is secreted by liver cells
ducts collect bile stored in gall bladder travels through ducts to pancreas pancreas and gall bladder ducts join up and secrete it into small intestine |
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Complete description of liver
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secretion of bile- emulsifies fats
carbohydrate metabolism - store/breakdown glycogen lipid metabolism - store/breakdown triglycerides protein metabolism - deamination processing of drugs, hormones - detox center |
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Complete description of liver continued
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excretion of bilirubin - bilirubin derived from aged RBC's
synthesis of bile salts - SI uses for emuls/absorption of lipids storage - glycogen, triglyc, vitamins a,b,d,e,k,minerals phagocytosis - RBC, WBC, bacterial activation of vitamin D - skin, liver, kidneys |
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Anatomy of the pancreas
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main duct empties 4inches below pyloric sphincter
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Describe panreatic cells
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acini-dark clusters
99% of gland produce pancratic juice islets of langerhorns 1% of gland produce hormones |
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Describe Pancreatic Juice
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1.5 L/day pH 7.1 - 8.2
water, enzymes, sodium bicarbonate digestive enzymes - pancreatic amylase, pancreatic lipase proteases: trypsinogen - trypsin chymotrypsinogen - activated by trypsin procarboxypeptidase - activated by trypsin |
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Regulation of Pancreatic Secretions
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secretin
-acidity in intestine - increased sodium bicarbonate release - inhibits gastric juices CCK - fats and proteins - increased production of pacreatic digestive enzyme release - inhibits gastric juices |
